PHP Extension - newbie question

Hi,

     I have been lurking on this list for a while, and this is my first post. Sorry it has to be such a daft question.  I don't even know if it's the right list, so my apologies in advance.

I need to add mysqli support to a web server and our sys admin refuses to do anything unless it comes from a debian package. Anyway I thought it would be possible to compile PHP in a chroot enviroment with mysqli support and take the extension and use that on our servers. I ran a simple ./configure --with-apxs2=/usr/bin/apxs2 --with-mysql=/usr/local/mysql --with-mysqli=/usr/local/mysql/bin/mysql_config --with-zlib --with-gd However I can't seem to find the extension. I ran php-config --extension-dir but it points to a directory that doesn't exist. The only good thing to come out of this, is that I now have an environment where I can easily test builds. George